var url ="https://douban-api.uieee.com/v2/movie/top250";
function http({type="get",callback,data={}}){
    $.ajax({
        url,
        data,
        type,
        dataType:"jsonp",
        success: function(res) {
            callback(res)
        }
    })
}
function onReachBottom(){
    var dh = $(document).height();
    var sh = $(window).scrollTop();
    var wh = $(window).height();
    return (Math.ceil(sh + wh) == dh) ? true : false;
}
